THE SKIN AND ITS APPENDAGES. 



371 



The papillae are large and very numerous around the arms, and pass by gradual, 

 transitionary stages into the ordinary papillae of the region. Further they may be 

 traced backwards along the anterior or extensor surface of the thigh, the upper surface 



Fig. 232. 



\ 



I. Diagram to show the distribution of the temporary papillae in Ratta 



temporaria ', after Huber. 



II, III. Vertical sections through a temporary papilla ; after Huber. 



of the leg, foot, and fifth toe. Occasionally a few papillae were found on flexor sur- 

 faces of the third and fourth metatarsus, and very rarely were any discovered on the 

 fore-limbs. They occur in no other batrachian of Germany (Huber \ 



Each papilla s Fig. 232 II and III) consists of a hemispherical elevation of the 

 cutis, and is covered either by a layer of normal epidermis or in seme very rare cases 

 the epidermis was slightly thickened. The papilla consists of a firm connective-tissue 

 stroina, and is from 0-2-0-4 mm. in height, 0-4-0-5 mm. broad (after hardening in 

 alcohol'. Such glands as exist in the papilla usually open laterally '^Fig. 232 III'j . 

 and the Mood- vessels are numerous. 



B b 2 



